Fiberglass Composite materials can be coated to show many different finished effects. I ran across a Youtube video demonstrating a spray on chrome process with a fiberglass molded piece.
It is interesting to see the change in appearance as the coating is applied. I am amazed at how wet the part is sprayed. Definitely not a traditional spray application method.
My guess is that the spraying with an air nozzle is working to help remove any runs and wrinkles in the surface finish.
This coating process will act like a painted surface more than a part that has been subjected to a hardened plating process. Surface adhesion will be very important to test the durability of the finished look.